Abstract:A relatively large number of the convective storms which affect Beijing and Hebei can often be traced to the Taihang Mountains. This study analyzes warm-season convective storms developing in the eastern foothills of the Taihang Mountains during 2011-2020. The statistical analysis is based on the national composite radar reflectivity factor data mosaics to increase the understanding of the evolution of these convective storms, including the changing of intensity, lifespan and so on. The results show that there are four high-frequency centers with strong echoes ≥45 dBz located in northern Shijiazhuang, southern Beijing, south-central Baoding and western Cangzhou. The storms often strengthen significantly in the foothills of northern Shijiazhuang and western Cangzhou. For the strengthened convective storms, they are most active in mountainous areas around 17:00 BT and mainly affect plain areas between 18:00 BT and 02:00 BT. The more westerly the path, the more cases of mountain-to-plain convective storms, the higher the percentage of convective intensification, and the greater the moving speed. During the downhill process, most convective storms become stronger and more organized. For the convective storms whose echo strength ≥45 dBz at the initial moment of going downhill, more than 86% of them can successfully reach the plains, and more than 90% of them with horizontal scale exceeding 100 km and solidly connected structures can successfully reach the plains. The strong echo areas of the strengthened convective storms expand dramatically as they go downhill. Strong echo areas expand to about 2 times larger than their initial echo areas when they reach the foothill, and the average areas in the plains can reach 4.6 times as big as their initial echo areas. Most of the strengthened convective storms take only 1-2 hours to go downhill and last 4-8 hours on the plains. The storm types of the convective storms which last 4-8 hours on the plains are dominated by linear MCS (47%) and nonlinear MCS (30%).